Karkinos is a calm thinker and not easily provoked. His purple Heroic Tribe form, "Lernaea", employs some sort of corrosive gas, or similar material, as a means of attack. It is implied that this power can destroy entire solar systems. Apparently, he is capable of resurrection. He is the first Nodos to fight against Age.
His name is based on Karkinos, a crab that tried to help a hydra defeat Heracles. Accordingly, Karkinos' Heroic Tribe form can transform into a type of hydra when on solid ground. Lernaea's main ability is thought to be Life, then revealed to be Restoration. He appears to have feelings for Yuty La, and states several times that he would protect her even if his labors didn't require it.
Karkinos' contract with the Silver Tribe contains 4 Labors.